1. Field of the Invention
The present invention relates, in general, to vectors comprising a Ketogulonigenium replicon. More specifically, the present invention relates to vectors comprising a Ketogulonigenium replicon found on the endogenous plasmid contained in Deposit No. NRRL B-30035.
2. Background Information
The exploitation of microorganisms to synthesize vitamin C or its chemical pathway intermediates has both economic and ecological advantages. One key intermediate in vitamin C synthesis is 2-keto-L-gulonic acid (2-KLG), which is easily converted chemically to L-ascorbic acid (vitamin C) by esterification followed by lactonization (Delic, V. et al., “Microbial reactions for the synthesis of vitamin C (L-ascorbic acid,” in Biotechnology of Vitamins, Pigments and Growth Factors, Vandamme, E. J., ed., Elsevier Applied Science (London & New York) pp. 299–336 (1989)). Members of a number of bacterial genera have been identified that produce 2-KLG from the oxidation of sorbitol. Such 2-KLG producing genera include the acidogenic, alpha-proteobacteria Gluconobacter and Acetobacter, the gamma-proteobacteria Pseudomonas, Escherichia, Klebsiella, Serratia and Xanthmonas, the Gram positive Bacillus, Micrococcus and the unofficial genus Pseudogluconobacter (Imai, K. et al., U.S. Pat. No. 4,933,289 (1990), Sugisawa, H. et al., “Microbial production of 2-keto-L-gulonic acid from L-sorbose and D-sorbitol by Gluconobacter melanogenus,” Agric. Biol. Chem. 54:1201–1209 (1990), Yin, G. et al., U.S. Pat. No. 4,935,359 (1990) and Nogami, I. et al., U.S. Pat. No. 5,474,924 (1995)).
To aid in increasing the yield of bacterial products, attempts have been made to exploit endogenous plasmids within microorganism strains. For example, shuttle vectors derived from endogenous plasmids have been utilized in an attempt increase production of bacterially generated compounds in Gluconobacter and Acetobacter (Beppu, T. et al., U.S. Pat. No. 5,580,782 (1996), Fujiwara, A. et al., U.S. Pat. No. 5,399,496 (1995), Tonouchi et al, U.S. Pat. No. 6,127,174 (2000), Hoshino, T. et al., U.S. Pat. No. 6,127,156, (2000)).